Thanks for your reply!
The good news: the "funky finger" cursor is GONE
The other news: the other behavior as shown in the GIF remains, namely:
When the song is playing, moving the mouse cursor anywhere into the spectrogram causes the MusicBee time indicator and progress bar in the player controls-bottom pane to freeze, although the music continues to play. Moving the cursor out of the spectrogram will cause the MB time and progress bar to un-freeze and immediately jump to the currently playing position.
As expected from the above behavior, clicking within the spectrogram for a seek operation is successful, but the MB time/bar will freeze, then unfreeze when the cursor is moved out of the display.
I said "other" news because this isn't exactly some big negative or bug, it just would be nice to have the player control indicators function as you would expect regardless of whether the cursor is in the spectrogram window or not. To which one might reply, "just keep it out of the window then, stupid!"
With the thousands of views this thread has received it would sure be nice to have some other users commenting on this (hint, hint!).
Anyway, it would be great if you feel like having another bash at this, and much appreciated by me at least. But if want to consign it to the "things that cannot be fixed" category, I'm good with that too.